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