In a glass bowl or plastic bag, combine the snapper filets with the lime juice, cilantro, garlic, serrano, salt and pepper. Marinate in the refrigerator for 2 hours. To prepare the peach salsa, combine all ingredients in a bowl. Toss gently so peaches and tomatoes are not damaged. Allow to sit for 10 to 15 minutes, so flavors can combine. Preheat the grill and grill the marinated snapper filets 3 to 4 minutes per side, until meat flakes easily with a fork. Cut the fish into small chunks to wrap in the warm tortillas, garnish with the peach salsa, shredded cabbage and a little more cilantro.