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