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