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