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