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