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