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