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