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)(13,14,19,21)(15,24,16,22)(17,23,18,27)(20,25,28,26)(5,6)(7,11)(8,10)(9,12)(13,15,18,26,19,16,17,25)(14,20,23,24,21,28,27,22)(2,4)(5,7)(6,9)(8,12)(10,11)(14,21)(20,28)(22,24)(23,27) involution — undirected(7,12)(9,11)(13,16,19,15)(14,22,21,24)(17,25,18,26)(20,23,28,27)(6,10)(9,11)(13,17,19,18)(14,23,21,27)(15,25,16,26)(20,24,28,22)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.