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