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