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