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