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