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