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)(11,20)(12,16)(13,18)(14,17)(15,22)(19,27)(21,28)(23,30)(24,34)(25,32)(26,31)(29,36)(33,38)(35,39)(37,40) involution — undirected(1,3,5,4)(2,6,8,7)(9,11,13,22)(10,15,18,20)(12,24,25,21)(14,23,27,36)(16,28,32,34)(17,29,19,30)(26,37,38,35)(31,39,33,40)(1,3,5,4)(2,7,8,6)(9,12,13,25)(10,16,18,32)(11,21)(14,26,27,38)(15,28)(17,31,19,33)(20,34)(22,24)(23,35)(29,39)(30,40)(36,37)(1,4,5,3)(2,6,8,7)(10,17)(14,27)(15,29)(16,31)(18,19)(20,30)(23,36)(26,38)(28,39)(32,33)(34,40)(35,37)A 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.