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