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