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