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