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