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