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