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)(11,18)(12,15)(13,21)(14,17)(16,22)(19,23)(20,24)(25,26,32,31)(27,36,30,33)(28,35,29,34)(37,39,38,40)(1,3,6,5)(2,7,4,8)(11,12)(13,22)(15,18)(16,21)(25,27,32,30)(26,33,31,36)(28,38,29,37)(34,40,35,39)(1,2,6,4)(3,7,5,8)(9,11,14,12)(10,15,17,18)(13,19,22,20)(16,23,21,24)(25,28,32,29)(26,34,31,35)(27,37,30,38)(33,39,36,40)(1,2,6,4)(3,8,5,7)(9,12,14,11)(10,15,17,18)(13,20,22,19)(16,23,21,24)(25,29,32,28)(26,35,31,34)(27,38,30,37)(33,40,36,39)(1,4,6,2)(3,7,5,8)(9,13)(10,16)(11,19)(12,20)(14,22)(15,23)(17,21)(18,24)(25,30,32,27)(26,36,31,33)(28,38,29,37)(34,40,35,39)(1,5,6,3)(2,7,4,8)(9,10)(11,18)(12,15)(13,16)(14,17)(19,24)(20,23)(21,22)(25,31,32,26)(27,36,30,33)(28,35,29,34)(37,40,38,39)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.