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