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