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