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