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