Place the diced potatoes in a pot of salted cold water and bring to a boil over medium-high heat. Cook until the potatoes are fork-tender, about 6-8 minutes. Drain well.
Place the potatoes in a single layer on a plate or baking sheet to allow them to cool more rapidly. Refrigerate to speed up the cooling process.
Mix together the potatoes, onion, celery, mayonnaise, and sriracha; season with salt & pepper to taste, then serve.