Stir together the mango, tomatoes, red onion, garlic, lime juice, cilantro, jalapeño, and salt in a small bowl to combine. Cover with plastic wrap and chill in the refrigerator until ready to use.
Whisk together the olive oil, lime juice, paprika, cayenne, salt, garlic powder, mustard, and oregano in a shallow baking dish. Add the shrimp and turn to coat evenly. Cover with plastic wrap and chill in the refrigerator for at least 1 hour.
Place a grill pan over medium-high heat. Add the shrimp and grill for 1 to 2 minutes per side, until cooked through. Separate the lettuce leaves and arrange the shrimp in the center of the leaves. Spoon the mango salsa over the top and serve.