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