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