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