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