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