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