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