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