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