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