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