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