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