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