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