In a large bowl, toss carrots, cabbage, and bean sprouts; add kelp powder and cayenne, mixing thoroughly. Cover vegetables with a plate that fits down into the bowl and place a weight on top of the plate. Refrigerate for 6 hours or overnight.
Drain off liquid and toss vegetables with sesame oil, soy sauce, lemon juice, and parsley. Garnish with shredded nori on top.