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