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