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