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