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