Grilled Zucchini with Tomatoes and Mozzarella

medium zucchini (cut on a bias 1/4-inch thick)

ball (8 ounce) fresh buffalo mozzarella (thinly sliced into rounds)

vine-ripe red and yellow tomatoes (1/4-inch slices)

extra-virgin olive oil (to drizzle)

aged balsamic vinegar (to drizzle)

kosher salt and freshly ground pepper

bunch fresh basil (chiffonade)