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