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