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