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