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