Cook pasta according to package direction. To prevent sticking run with cold water or add a pinch of salt to the water while boiling. Add noodles to a large mixing bowl with onion, bell peppers, and celery.
In a separate mixing bowl whisk together mayonnaise, sugar, vinegar, and yellow mustard until well combined and smooth.
Pour your mayo dressing into the large mixing bowl and toss until coated. Add cubed cheese and toss again. Allow to chill for 2-3 hours int he fridge then serve.