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