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