You already have about the best CPU that motherboard can use. If you were to say why you want to upgrade it might get you better advice on what your next move should be. It's hard to advise someone when you don't know what their needs are.
As the others have said, I wouldn't look at any chip on the FX series any more. The chip while has been updated and has had some increases in performance, is now only on par with an I7 2700. I would honestly look at the Ryzen boards since AMD has said that they are keeping the socket until 2020 which is going to give you some other options to upgrade with.