Mix tomatoes, celery, carrots, bell pepper, cucumber, and onion together in a large bowl. Add cooled pasta, salad dressing, and Parmesan; mix until well combined. Cover and chill for 1 hour before serving.
Bring a large pot of lightly salted water to a boil; cook pasta at a boil until tender yet firm to the bite, about 8 minutes. Rinse under cold water, and drain.
