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