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