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