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