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