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