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