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