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