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