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