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