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