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