One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,3)(6,10)(7,8)(11,12)(13,14,18,21,17,16,23,20)(15,22,25,27,24,19,26,28)(2,3)(6,11)(10,12)(13,15,23,26,17,24,18,25)(14,19,20,27,16,22,21,28)(5,6)(7,10)(8,12)(9,11)(13,16)(14,17)(15,19)(18,20)(21,23)(22,24)(25,28)(26,27) involution — undirected(1,3,4,2)(5,7,9,8)(6,10,11,12)(14,16)(19,22)(20,21)(27,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.