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