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