Preheat the oven to 425°F (220°C).
Toss the cubed sweet potatoes with olive oil, salt, and black pepper.
Spread on a parchment-lined baking sheet and roast for 20–25 minutes, turning once, until tender and lightly caramelized.
Allow the sweet potatoes to cool for 15–20 minutes.
Whisk together the mayonnaise, Dijon mustard, apple cider vinegar, honey, smoked paprika, garlic powder, salt, and pepper.
Add the cooled sweet potatoes, chopped eggs, celery, red onion, green onions, and parsley to a large bowl.
Add the dressing and gently fold until everything is lightly coated.
Cover and refrigerate for at least 30 minutes before serving.