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