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