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