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