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