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