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