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