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