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