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