Cook the Macaroni: Bring a large pot of salted water to a boil. Add the elbow macaroni and cook according to package instructions until al dente. Drain and rinse under cold water to cool.
Prepare the Dressing: In a mixing bowl, combine the mayonnaise, Dijon mustard, apple cider vinegar, garlic powder, onion powder, salt, and pepper. Whisk until smooth and well combined.
Mix in Vegetables: In a large bowl, add the cooled macaroni, diced celery, red bell pepper, red onion, and sweet pickle relish. Gently toss to combine.
Add Dressing: Pour the dressing over the macaroni and vegetables. Gently fold in the chopped hard-boiled eggs, taking care not to break them down too much.
Chill: Cover the bowl with plastic wrap and chill in the refrigerator for at least 1 hour to allow the flavors to meld together.
Serve: Before serving, taste and adjust seasoning with salt and pepper as necessary. Garnish with fresh parsley for a pop of color.
Notes
Serve in a decorative bowl and garnish with parsley and lemon wedges.