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