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