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