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