One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,8)(9,12)(10,11)(14,17)(15,20)(22,25)(23,27) involution — undirected(1,2,3,4)(5,7)(6,10)(8,12)(9,11)(13,14)(15,19)(16,17)(18,20)(1,2)(3,4)(5,7)(6,10)(8,12)(9,11)(13,15)(14,18)(16,20)(17,19)(21,22,24,25)(23,26,27,28)(5,7)(6,8)(9,11)(10,12)(13,15)(14,19)(16,20)(17,18) involution — undirected(5,8)(6,11)(7,12)(9,10)(13,14)(15,18)(16,17)(19,20)(21,23)(22,26)(24,27)(25,28) involution — undirectedA 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.