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)(11,15)(12,17)(13,23)(14,19)(16,22)(18,20)(21,24)(25,26,32,29)(27,35,31,33)(28,34,39,30)(36,37,38,40)(2,5)(6,7)(9,11,14,21)(10,15,19,24)(12,20,22,13)(16,23,17,18)(25,27,32,31)(26,33,29,35)(28,36,39,38)(30,37,34,40)(1,2)(3,6)(4,5)(7,8)(9,12)(10,16)(11,20)(13,21)(14,22)(15,23)(17,19)(18,24)(25,28,32,39)(26,34,29,30)(27,36,31,38)(33,40,35,37)(1,3,4,8)(2,6,5,7)(9,12)(10,17)(11,20)(13,21)(14,22)(15,18)(16,19)(23,24)(25,29,32,26)(27,33,31,35)(28,30,39,34)(36,40,38,37)(9,10)(11,15)(12,16)(13,18)(14,19)(17,22)(20,23)(21,24)(25,30)(26,28)(27,37)(29,39)(31,40)(32,34)(33,36)(35,38) involution — undirected(9,13,14,20)(10,18,19,23)(11,12,21,22)(15,16,24,17)(25,31,32,27)(26,33,29,35)(28,38,39,36)(30,37,34,40)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.