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