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