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