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