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