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