Boil pasta in salted water until al dente, about 8-10 minutes; drain and rinse with cold water.
Chop cherry tomatoes, bell peppers, red onion, cucumber, olives, and parsley.
Whisk olive oil, red wine vinegar, Dijon mustard, garlic powder, oregano, basil, salt, and pepper for dressing.
Toss pasta, vegetables, mozzarella, and dressing in a large bowl.
Refrigerate for 15-30 minutes; garnish with Parmesan and parsley before serving.