In a large mixing bowl, combine the diced tomatoes, cucumbers, bell peppers, and shredded cheddar cheese.
In a separate bowl, whisk together the mayonnaise, apple cider vinegar, garlic powder, onion powder, salt, and black pepper until smooth.
Pour the dressing over the vegetable mixture and stir until everything is well coated.
Gently fold in the crushed saltine crackers until evenly distributed.
Cover the salad and refrigerate for at least 1 hour to allow the flavors to meld.
Before serving, garnish with sliced green onions.