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