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