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