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