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