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