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)(25,26,31,32)(27,35,36,33)(28,38,37,34)(29,30,39,40)(1,3,6,5)(2,7,8,4)(9,11)(10,15)(12,20)(13,16)(14,19)(17,21)(18,22)(23,24)(26,32)(27,36)(29,39)(34,38)(2,8)(3,5)(11,19)(12,21)(15,22)(16,24)(25,27,31,36)(26,33,32,35)(28,29,37,39)(30,38,40,34)(1,3,6,5)(2,7,8,4)(9,12)(10,16)(11,20)(13,15)(14,21)(17,19)(18,24)(22,23)(25,28,31,37)(26,34,32,38)(27,29,36,39)(30,35,40,33)(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)(26,30)(27,37)(28,36)(31,39)(32,40)(33,38)(34,35)(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)(26,29)(27,38)(28,35)(31,40)(32,39)(33,37)(34,36)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.