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