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