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