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