One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,10)(9,12)(13,14)(15,23)(16,22)(17,21)(18,20)(19,26)(24,27)(25,28) involution — undirected(1,2)(3,4)(5,7,8,12)(6,9,10,11)(13,14,17,21)(15,23,24,27)(16,22,18,20)(19,25,28,26)(13,15,17,24)(14,19,21,28)(16,26,18,25)(20,23,22,27)(2,4)(14,20)(15,24)(16,18)(19,27)(21,22)(23,28) involution — undirected(6,10)(9,11)(13,16,17,18)(14,20,21,22)(15,25,24,26)(19,27,28,23)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.