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