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