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