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