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