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