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