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