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