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