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