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