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