CHRISTIANS: Why Do You Need Proof That The Flying Spaghetti Monster Exists...?
If she did show herself, then what good would that do? TFSM wants to see your true colors.
Plus, even if she did show herself, we would all go blind and die. TFSM is so pure and holy, that our sinful selves would go blind and die if saw the light of The Flying Spaghetti Monster's Glory.
So believe in her, or don't. It's your life, TFSM gave you free will.