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