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)(14,22)(18,24)(19,20)(21,23)(25,26,31,35)(27,34,30,32)(28,29,33,40)(36,37,38,39)(1,3,6,4)(2,7,5,8)(9,11)(10,16)(12,20)(13,22)(14,17)(15,19)(18,23)(21,24)(25,27,31,30)(26,32,35,34)(28,36,33,38)(29,39,40,37)(10,12)(11,19)(17,21)(18,22)(25,27,31,30)(26,32,35,34)(28,38,33,36)(29,37,40,39)(9,12,15,10)(11,20,19,16)(13,21,23,17)(14,22,24,18)(25,28,31,33)(26,29,35,40)(27,36,30,38)(32,39,34,37)(1,4,6,3)(2,7,5,8)(9,13,15,23)(10,17,12,21)(11,18,19,22)(14,16,24,20)(25,29)(26,33)(27,37)(28,35)(30,39)(31,40)(32,36)(34,38)(1,5,6,2)(3,8,4,7)(9,14)(10,18)(11,17)(12,22)(13,20)(15,24)(16,23)(19,21)(25,30,31,27)(26,34,35,32)(28,38,33,36)(29,37,40,39)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.