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