Cook the rotini pasta according to package instructions. Drain and rinse under cold water to cool.
In a large bowl, combine the cooled pasta, diced chicken, crumbled bacon, cherry tomatoes, cucumber, red onion, and shredded lettuce.
In a separate small bowl, whisk together the mayonnaise, Dijon mustard, apple cider vinegar, salt, and pepper until smooth.
Pour the dressing over the pasta salad and toss gently until all ingredients are well coated.
Cover the bowl and refrigerate for at least 30 minutes to allow flavors to meld.
Serve chilled or at room temperature.