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