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