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)(20,24)(25,27)(26,28) involution — undirected(1,2)(3,4)(13,15)(14,20)(16,23)(17,24)(18,26)(19,25)(21,27)(22,28) involution — undirected(2,4)(6,9)(10,12)(13,16,19,21)(14,17,22,18)(15,23,25,27)(20,24,28,26)(2,4)(13,14)(15,20)(16,17)(18,21)(19,22)(23,24)(25,28)(26,27) involution — undirected(5,7,8,11)(6,10,9,12)(13,17,19,18)(14,21,22,16)(15,24,25,26)(20,27,28,23)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.