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