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