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