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