I did the same thing to my carpet and this is the best answer I have seen on here yet. If you don't have any spare chunks of carpet around you can steal some small clippings from the corner of your carpet where it won't be seen. The best place to steal clippings from are from a corner under the moldings or inside a closet. Good luck!
In the future you might want to put a cheap carpet under your hookah. When you burn that one, you can just throw it away.