So I am trying to translate the sentence "Are you still waiting for me?" and I have translated it to "僕にとってまだ待っているのか?". Would this be a natural sentence or is it possible to make the sentence shorter?
待つ is a transitive verb, meaning that you can use it with an object. を marks objects of action, so it would be correct to say 僕を待つ to mean "wait for me". There are probably a trillion ways to say what you want, but this I think would be the straightforward choice:
You can of course just shorten it to "[are you] still waiting?" まだ待っているのか