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