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