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