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