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