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