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)(13,14,19,15)(16,20,25,23)(17,22,18,21)(24,26,28,27)(1,2,3,4)(6,9)(10,11)(13,15,17,22,19,14,18,21)(16,24,26,23,25,28,27,20)(5,7,8,12)(6,10,9,11)(13,16)(14,20)(15,23)(17,27)(18,26)(19,25)(21,28)(22,24)(13,15,19,14)(16,23,25,20)(17,21,18,22)(24,27,28,26)(16,25)(20,23)(24,28)(26,27) 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.