Sorry this has happened to your dragon. But cats and lizards In the same house are a recipy for a disaster and badly injured lizard or a dead one unless you are extremely careful and very diligent about ensuring the room the dragon lives in (in it's tank) is a CAT EXCLUSION ZONE and everyone in the household makes sure it stays that way.
If you are lucky it's evaded the cat . .
Are there are any scratches that have broken the skin ?
, or penetrating claw or fan impaling wounds ?
if there are this is VERY BAD and a vet ER emergency , you will need to get the injured dragon to a reptile vet right away as It's essential to get it xrayed and thoroughly examined and wound's cleaned up in surgery and to start the reptile on a course of carefully targeted very powerful broad spectrum antibiotics to try to head of the inevitable life threatening systemic infection that kills most animals attacked by cats. Please don't even consider home remedies such as raw honey as an alternative. The longer you delay starting getting started with antibiotics under a vet's supervision the worse the dragon's prognosis.
This happens lots .
Kid next door to me had a breeding colony of jacky dragons in his bedroom and his elder sister decided she wanted a cat . Came home from school one afternoon to find 5 of the 6 jacky dragons out of the cage a spread out all over the house either dead or dying . Someone forgot to close the bedroom door , and the cat had all day after the kids went to school to rip open the wire mesh lid on the jacky dragon tank and then fish out the dragons one at a time , torture them until they became "boring" than go and get another .
The cat knows there is a reptile in the house now , you'll be hard pressed keeping the cat away from it and stopping it from attacking the dragon from now on . You need to make the tank cat proof .
There are four options for housing your dragon SAFELY from here forward :
option 1 : convert existing tank to a solid timber hinged lid
viewtopic.php?f=75&t=240221&p=1840683#p1840683
option 2 : convert existing tank by add sliding glass (lockable) doors
option 3 : move the dragon into a tub with a click clak style lid that has been modified , a 120L tub will be ideal for a juvenile up til it's first birthday ie
https://www.bunnings.com.au/all-set-120l-plastic-storage-container_p2583852 , conversion is easy and quick
, and the latches that hold the lid on will make it cat proof ie
viewtopic.php?f=34&t=233480
option 4 : invest in a solid timber front opening tank or build one for the dragon.
OR you can put an electrified grid on top and infront so the cat gets a jolt of current as soon as it touches the grid.
You've likely learnt a hard lesson and the dragon could have paid the price for cat lovers here saying cats and lizards can live together and be pals.