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