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