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