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