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