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