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