In an extra-large bowl combine squash, sweet peppers, beans, carrots, cherry sweet peppers, oil, salt, and black pepper; toss to combine. In a small bowl stir together lemon peel, lemon juice, and garlic; set aside.
Lightly coat an unheated grill wok with nonstick cooking spray. Place the vegetables in the wok. For a charcoal grill, place the wok on the rack of an uncovered grill directly over medium coals. Grill for 30 to 35 minutes or until vegetables are crisp-tender and light brown, stirring occasionally. (For a gas grill, preheat grill. Reduce heat to medium. Place wok on grill rack over heat. Cover and grill as directed.)
Return cooked vegetables to the bowl. Add the lemon mixture; toss to coat. To serve, arrange vegetables on a large platter.