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