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