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