Place the diced potatoes in the bottom of the pressure cooker. Add 1 1/2 cups water. Place the rack on top of the potatoes and then the eggs on the rack. Cover and make sure the vent is set to closed. Press the Rice/Risotto button for a total of 6 minutes on high. Meanwhile, chop the onion and celery. When the timer goes off on the cooker, let the pressure release naturally. Remove the eggs to an ice bath for a couple of minutes. Drain the water from the potatoes and place them into a medium-size mixing bowl. Peel the eggs and put two back for garnish. Chop the remaining eggs and add them to the potatoes. Add the onion, celery, relish, Miracle Whip, mustard, salt, and pepper to taste. Mix well. Taste to see if you need to adjust any ingredients. If your potato salad is to your liking, use a spoon to smooth out the potato salad and top with slices of the two remaining eggs. Sprinkle with paprika for garnish. This can be served warm or cover and chill overnight to let the flavors come out better.