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