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