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