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