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