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