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