Coat cold cooking grate of grill with cooking spray, and place on grill. Preheat grill to 350° (medium) heat.
Sprinkle tomatoes with salt; let stand 15 minutes. Pat tomatoes dry with paper towels.
Grill peach slices, covered with grill lid, 2 to 3 minutes on each side or until grill marks appear.
Place dough on a large baking sheet coated with cooking spray; lightly coat dough with cooking spray. Roll dough to 1/4-inch thickness (about 14 inches in diameter). Slide pizza dough from baking sheet onto cooking grate.
Grill, covered with grill lid, 2 to 3 minutes or until lightly browned. Turn dough over, and reduce temperature to 250° to 300° (low) heat; top with tomatoes, grilled peaches, and mozzarella. Grill, covered with grill lid, 5 minutes or until cheese melts. Arrange basil leaves over pizza. Serve immediately. Garnish, if desired.