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)(15,22)(16,26)(17,21)(18,23)(19,20)(24,28)(25,27) involution — undirected(1,2)(3,4)(6,10)(11,12)(13,15,18,19)(14,20,23,22)(16,24,27,21)(17,25,28,26)(2,4)(5,7,9,8)(6,11,10,12)(13,16,15,24,18,27,19,21)(14,17,20,25,23,28,22,26)(1,2)(3,4)(5,8,9,7)(6,12,10,11)(13,17,18,28)(14,21,23,24)(15,25,19,26)(16,22,27,20)(2,4)(13,15,18,19)(14,22,23,20)(16,24,27,21)(17,26,28,25)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.