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