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