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