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