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