Spray a large nonstick skillet with cooking spray; heat over medium heat. Add Egg Beaters, season with salt and pepper. Cook until edges and bottom begins to set, about 4 minutes. Gently scramble; continue cooking until cooked; an additional 2 minutes.
Heat fully cooked refried beans in microwave and spread on tostada shells. Top with scrambled egg beaters, diced tomatoes, cilantro and queso fresco.