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