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