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