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