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