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