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