If you think you'll continue to mar the frame under the safety...
Slide a thin piece of sandpaper (emory cloth) face up, under the safety, and work the lever back and forth to remove anything under the lever that's protruding and marring the finish.
The safety itself doesn't have to rub against the frame, and there are both springs and adetent INSIDE the frame to keep the safety lever IN the gun and to allow it to "click" postively into both the on and off positions.
(You could also remove the safety lever and do the job more completely and repaint the underside of the lever when you're done... but unless you've done that sort of work on a CZ before, it's a little tricky. Not rocket science, but more complicated than field stripping.)