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