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