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