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