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