Cook the noodles per package directions. If you are using uncooked shrimp, you can add it to the pot during the last 3 minutes of cooking. Drain.
While the noodles are cooking, combine the dressing ingredients in a lidded mason jar and shake to emulsify.
Place the noodles, shrimp, napa cabbage, snow peas and bean sprouts in a large bowl. Pour the dressing over and toss to combine. Serve with thinly sliced green onions and cilantro if desired.