Oneway,
I'm unfamiliar with catalyst center and ATI cards in general but there's 2 place you can adjust the AA.
First on the opening page where you select online/offline play,goto video settings,you'll see an AA slider there,move this all the way to the right.
Then in your graphic card settings,I assume in the catalyst center,try 4x and see how things run,if you still hold 60FPS and that doesnt get rid of the jagged edges,try 8x.
Be warned this will put a strain on the vidcard but from the specs you've listed it shouldn't be an issue.
Hope that helps,keep us informed of your progress.
