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