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