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