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)(11,20)(12,13)(14,19)(15,17)(16,22)(18,23)(21,24)(25,26,30,32)(27,31,35,37)(28,36,38,33)(29,34,39,40)(1,3,5,8)(2,6,4,7)(9,11,15,22)(10,16,17,20)(12,19,18,24)(13,21,23,14)(25,27,30,35)(26,31,32,37)(28,34,38,40)(29,36,39,33)(1,2,5,4)(3,6,8,7)(10,17)(12,18)(16,20)(19,24)(26,32)(27,35)(33,36)(34,40)(1,4,5,2)(3,7,8,6)(9,12,15,18)(10,13,17,23)(11,19,22,24)(14,16,21,20)(25,26)(27,31)(28,33)(29,34)(30,32)(35,37)(36,38)(39,40)(9,13)(10,18)(11,21)(12,17)(14,22)(15,23)(16,24)(19,20)(25,28)(26,33)(27,34)(29,31)(30,38)(32,36)(35,40)(37,39) involution — undirected(9,14,15,21)(10,19,17,24)(11,13,22,23)(12,16,18,20)(25,29)(26,34)(27,36)(28,37)(30,39)(31,38)(32,40)(33,35)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.