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