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