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