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