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