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