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