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)(25,26,31,33)(27,34,37,30)(28,32,38,29)(35,36,40,39)(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)(26,30)(28,35)(29,36)(31,37)(32,39)(33,34)(38,40)(2,5)(3,7)(10,14)(13,18)(16,20)(21,23)(25,28,31,38)(26,32,33,29)(27,35,37,40)(30,39,34,36)(3,7)(6,8)(9,12)(10,16)(11,19)(13,23)(14,20)(15,22)(17,24)(18,21)(25,26)(27,30)(28,32)(29,38)(31,33)(34,37)(35,39)(36,40) 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)(25,29,31,32)(26,28,33,38)(27,36,37,39)(30,35,34,40)(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)(26,27)(28,36)(29,35)(31,34)(32,40)(33,37)(38,39)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.