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