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