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