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