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)(13,14)(15,25)(16,26)(17,21)(18,22)(19,24)(20,23)(27,28)(5,7,10,8)(6,11,9,12)(13,15,18,17)(14,21,22,25)(16,23,28,24)(19,27,20,26)(2,4)(5,8,10,7)(6,11,9,12)(13,16,18,28)(14,15,22,17)(19,21,20,25)(23,27,24,26)(5,9,10,6)(7,12,8,11)(13,17,18,15)(14,16,22,28)(19,27,20,26)(21,23,25,24)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.