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