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