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