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