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