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