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