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