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