Cook the angel hair pasta according to package instructions. Drain and rinse under cold water to cool. Set aside.
In a large bowl, combine the cooked pasta, bell peppers, cucumber, carrots, red cabbage, green onions, and cilantro. Toss gently to mix.
In a separate bowl, whisk together the peanut butter, soy sauce, rice vinegar, honey or maple syrup, sesame oil, and sriracha (if using). Gradually add water until the dressing reaches your desired consistency.
Pour the peanut dressing over the pasta and vegetables. Toss until everything is well coated.
Chill in the refrigerator for at least 30 minutes before serving to allow the flavors to meld.
Serve cold and enjoy!