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