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