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