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