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