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