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