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