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