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