1Stir together vinegar, oil, oregano, mustard, pepper and garlic in small bowl.
2Place cucumber, onion, bell peppers and tomatoes in heavy-duty resealable plastic bag. Pour vinegar mixture over vegetables; seal bag and shake. Refrigerate at least 4 hours to blend flavors.
3Line serving platter with lettuce. Drain vegetables. Arrange vegetables and turkey slices on lettuce. Serve with buns.