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