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