One of the reasons I love coleslaw is that you can put the dressing on ahead of time and store the salad in the fridge, unlike many other salads. Put it on right away and let the shredded cabbage marinate in the dressing awhile. You'll notice that the coleslaw kind of "shrinks" after it's been refrigerated an hour or so. It looks like that because the cabbage has softened and settled a little. That's good! It's what you want it to do.