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