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