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