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