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