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