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