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