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