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