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