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