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