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