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