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