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