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