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