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