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