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