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