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