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