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