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