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