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