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