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