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