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