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