this adjective has no masculine or femenine; thus, you may say
questa persona è un/una superstite
(using the article "un" for man and
"una") for woman.

I suppose you don't mean "survivor" in the strictest sense: i.e. the person who survived a disaster, such as a fire, or a car crash or an earthquake.

If you mean that the person is a fighter, one who never dies, a tough act etc. then I suggest what follows.
Keep in mind that without appropriate contest, or knowing which tone exactly you intend to take, whether it is spoken or written, the answer is just a suggestion:

duro (masc. singular)
dura (fem. singular)
e una persona che non demorde (singular, for both masculine and feminine)
e una persona che non molla mai
(same)