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