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