One vertex per element, one color per generator, with an edge from x to x·s.
(2,6)(3,4)(9,10,13,16)(11,17,18,14)(12,20,21,15)(19,22,24,23)(25,26,29,31)(27,33,28,36)(30,39,38,34)(32,37,40,35)(1,2)(3,7)(4,8)(5,6)(9,11)(10,14)(12,19)(13,18)(15,22)(16,17)(20,23)(21,24)(26,31)(27,28)(34,39)(35,37) involution — undirected(2,6)(7,8)(25,27,29,28)(26,32,31,40)(30,37,38,35)(33,34,36,39)(1,3,5,4)(2,7,6,8)(11,18)(14,17)(19,24)(22,23)(25,28,29,27)(26,33,31,36)(30,37,38,35)(32,34,40,39)(1,4,5,3)(2,7,6,8)(9,12,13,21)(10,15,16,20)(11,19,18,24)(14,22,17,23)(26,31)(27,28)(34,39)(35,37)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.