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