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)(15,23)(16,18)(17,21)(19,22)(20,24)(25,27)(26,28) involution — undirected(1,2)(3,4)(6,9)(10,12)(13,15,18,26,19,25,17,24)(14,20,21,27,22,28,16,23)(2,4)(5,7,8,11)(6,10,9,12)(13,16,17,22,19,21,18,14)(15,23,24,28,25,27,26,20)(1,2)(3,4)(13,17,19,18)(14,21,22,16)(15,24,25,26)(20,27,28,23)(2,4)(15,25)(20,28)(23,27)(24,26) 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.