One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,3)(5,6)(7,9)(8,10)(11,12)(13,14,16,19,17,20,23,26)(15,18,22,25,21,24,27,28)(2,3)(5,7,8,11)(6,9,10,12)(13,15)(14,18)(16,22)(17,21)(19,25)(20,24)(23,27)(26,28)(6,10)(9,12)(13,15)(14,18)(16,22)(17,21)(19,25)(20,24)(23,27)(26,28) involution — undirected(1,3,4,2)(15,21)(18,24)(22,27)(25,28) 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.