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