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