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