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