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