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