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