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