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