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