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