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