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