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