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