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