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