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