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