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