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