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