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)(13,14,19,23)(15,24,25,21)(16,18,26,20)(17,22,27,28)(1,2,4,3)(5,7)(6,9)(8,11)(10,12)(13,15,19,25)(14,21,23,24)(16,22,26,28)(17,20,27,18)(6,10)(7,11)(13,16)(14,18)(15,22)(17,21)(19,26)(20,23)(24,27)(25,28) involution — undirected(6,10)(9,12)(13,17,20,25,19,27,18,15)(14,22,16,21,23,28,26,24)(1,3,4,2)(13,18,19,20)(14,16,23,26)(15,17,25,27)(21,22,24,28)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.