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