The quilt is 84" x 84", and king beds are 76" x 80" (Cal king is 72" x 84"). So the top (and most visible part) of the mattress would essentially be covered by the quilt. You could put large borders as the overhang and I think it would look fine, especially if they were a dark tone-on-tone fabric. Dark or black borders would just recede into the background and allow the focus to remain on the center of the quilt.
Normally my answer would be to add more rows, but in the case of this quilt, I think you would lose the symmetry of the maze.