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