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