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