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