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