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