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