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