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)(11,12)(13,21)(14,16)(15,19)(17,22)(18,23)(20,24)(25,26)(27,30)(28,37)(29,35)(31,33)(32,36)(34,38)(39,40)(1,2)(3,6)(4,7)(5,8)(9,11,14,19)(10,15,16,12)(13,18,22,24)(17,23,21,20)(25,27,31,36)(26,32,33,30)(28,29,38,40)(34,35,37,39)(1,3,5,4)(2,6,8,7)(10,16)(12,15)(17,21)(20,23)(26,33)(27,36)(28,38)(35,39)(1,3,5,4)(2,6,8,7)(9,12)(10,11)(13,20)(14,15)(16,19)(17,18)(21,24)(22,23)(25,28)(26,34)(27,29)(30,39)(31,38)(32,35)(33,37)(36,40)(9,11)(10,12)(13,18)(14,19)(15,16)(17,20)(21,23)(22,24)(25,29)(26,35)(27,28)(30,37)(31,40)(32,34)(33,39)(36,38) involution — undirected(1,4,5,3)(2,7,8,6)(9,13,14,22)(10,17,16,21)(11,18,19,24)(12,20,15,23)(25,30,31,32)(26,36,33,27)(28,39,38,35)(29,34,40,37)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.