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