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