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