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