Use a flat vegetable peeler or mandoline to shave the zucchini into thin ribbons. Toss them in a large bowl along with the remaining salad ingredients.
Working over a medium bowl, use the coarse holes of a box grater to grate the cut sides of each tomato down to the skin. Discard the skin and whisk in the remaining dressing ingredients. Serve the salad topped with the vinaigrette.