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