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