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