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